Objective: To describe the clinical findings in patients with acute idiopathic blind spot enlargement (AIBSE).
Methods: Medical record review of 27 patients with AIBSE (without sufficient optic nerve head swelling to cause blind spot enlargement) seen in 2 academic neuro-ophthalmology units.
Results: All patients were women aged between 19 and 53 years. Twenty-three patients reported positive visual phenomena. Visual acuity was normal in 16 patients. All patients had enlarged blind spots of variable size and density. Dyschromatopsia and afferent pupil defects were prevalent. Ophthalmoscopic features included uveitis, mild optic nerve swelling, granularity of macular pigment, subretinal white dots, and peripapillary pigment disturbances. Twelve of the 13 patients who underwent fluorescein angiography had optic disc staining and 5 had retinal pigment epithelial lesions with late staining. Full-field electroretinogram results were normal in 8 of 9 patients, although focal electroretinogram results were abnormal in 8 of 9 patients. Photopsia always decreased but visual fields did not improve. Six patients experienced recurrence.
Conclusions: The clinical features of AIBSE include photopsia, visual field defects, abnormal findings from fundoscopic and fluorescein angiography, and abnormal results of focal electroretinography. The disease affects the peripapillary retina and may cause an afferent pupillary defect. The striking predilection for the peripapillary retina suggests a local etiologic factor and distinguishes AIBSE from the multiple evanescent white dot syndrome. Unlike patients with multiple evanescent white dot syndrome, recovery of visual field did not occur in patients with AIBSE.